On 30/10/17 08:35, Fengguang Wu wrote:

On Sun, Oct 29, 2017 at 11:51:55PM +0100, Fengguang Wu wrote:

quoted

Hi Linus,

Up to now we see the below boot error/warnings when testing v4.14-rc6.

They hit the RC release mainly due to various imperfections in 0day's
auto bisection. So I manually list them here and CC the likely easy to
debug ones to the corresponding maintainers in the followup emails.

boot_successes: 4700
boot_failures: 247

[...]

quoted

WARNING:at_kernel/jump_label.c:#static_key_disable_cpuslocked: 7

This patch is in the tip tree only, it will be merged in 4.15. So I
don't understand why you are reporting this for 4.14-rc6.

There is a patch by Dou Liyang pending since 28th October addressing
that issue:

[PATCH tip v2] x86/paravirt: Make the virt_spin_lock_key setup after
jump_label_init()


Juergen

The call trace is

[    0.000000] Booting paravirtualized kernel on bare hardware
[    0.000000] clocksource: refined-jiffies: mask: 0xffffffff
max_cycles: 0xffffffff, max_idle_ns: 1910969940391419 ns
[    0.000000] setup_percpu: NR_CPUS:8192 nr_cpumask_bits:72
nr_cpu_ids:72 nr_node_ids:2
[    0.000000] percpu: Embedded 39 pages/cpu @ffff88103f400000 s120088
r8192 d31464 u262144
[    0.000000] pcpu-alloc: s120088 r8192 d31464 u262144 alloc=1*2097152
[    0.000000] pcpu-alloc: [0] 00 01 02 03 04 05 06 07 [0] 08 09 10 11
12 13 14 15 [    0.000000] pcpu-alloc: [0] 16 17 36 37 38 39 40 41 [0]
42 43 44 45 46 47 48 49 [    0.000000] pcpu-alloc: [0] 50 51 52 53 -- --
-- -- [1] 18 19 20 21 22 23 24 25 [    0.000000] pcpu-alloc: [1] 26 27
28 29 30 31 32 33 [1] 34 35 54 55 56 57 58 59 [    0.000000] pcpu-alloc:
[1] 60 61 62 63 64 65 66 67 [1] 68 69 70 71 -- -- -- -- [    0.000000]
static_key_disable_cpuslocked(): static key
'virt_spin_lock_key+0x0/0x20' used before call to jump_label_init()
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:161
static_key_disable_cpuslocked+0x6c/0x80
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted
4.14.0-rc6-00162-g3d6dabc2 #1
[    0.000000] Hardware name: Intel Corporation S2600WTT/S2600WTT, BIOS
SE5C610.86B.01.01.0008.021120151325 02/11/2015
[    0.000000] task: ffffffff81e10480 task.stack: ffffffff81e00000
[    0.000000] RIP: 0010:static_key_disable_cpuslocked+0x6c/0x80
[    0.000000] RSP: 0000:ffffffff81e03e98 EFLAGS: 00010092 ORIG_RAX:
0000000000000000
[    0.000000] RAX: 000000000000006f RBX: ffffffff81e36fc0 RCX:
ffffffff81e60cf8
[    0.000000] RDX: 0000000000000001 RSI: 0000000000000092 RDI:
0000000000000047
[    0.000000] RBP: ffffffff81e03ea8 R08: 6b5f636974617473 R09:
000000000000018c
[    0.000000] R10: 0000000000000000 R11: 000000000000006f R12:
ffff88207ffcf4c0
[    0.000000] R13: ffffffff82170920 R14: ffffffff8218b780 R15:
0000000000000000
[    0.000000] FS:  0000000000000000(0000) GS:ffff88103f400000(0000)
knlGS:0000000000000000
[    0.000000] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.000000] CR2: ffff88207f4e0000 CR3: 000000207ee09000 CR4:
00000000000606b0
[    0.000000] Call Trace:
[    0.000000]  static_key_disable+0x1a/0x30
[    0.000000]  native_pv_lock_init+0x1b/0x1e
[    0.000000]  native_smp_prepare_boot_cpu+0x32/0x35
[    0.000000]  start_kernel+0x14f/0x421
[    0.000000]  x86_64_start_reservations+0x2a/0x2c
[    0.000000]  x86_64_start_kernel+0x72/0x75
[    0.000000]  secondary_startup_64+0xa5/0xb0
[    0.000000] Code: 85 c0 75 2f 48 c7 c7 20 5e f0 81 e8 df 2a 7b 00 5b
41 5c 5d c3 48 89 fa 48 c7 c6 40 93 a3 81 48 c7 c7 00 8b cb 81 e8 95 b5
f3 ff <0f> ff eb a8 0f ff eb b3 48 89 df e8 14 fc ff ff eb c7 66 90 e8
[    0.000000] ---[ end trace c12d07f00399ce78 ]---
[    0.000000] Built 2 zonelists, mobility grouping on.  Total pages:
33006159
[    0.000000] Policy zone: Normal

which is bisected to

commit 9043442b43b1fddf202591b84702863286700c1a
Author:     Juergen Gross [off-list ref]
AuthorDate: Wed Sep 6 19:36:24 2017 +0200
Commit:     Ingo Molnar [off-list ref]
CommitDate: Tue Oct 10 11:50:12 2017 +0200

   locking/paravirt: Use new static key for controlling call of
virt_spin_lock()

   There are cases where a guest tries to switch spinlocks to bare metal
   behavior (e.g. by setting "xen_nopvspin" boot parameter). Today this
   has the downside of falling back to unfair test and set scheme for
   qspinlocks due to virt_spin_lock() detecting the virtualized
   environment.

   Add a static key controlling whether virt_spin_lock() should be
   called or not. When running on bare metal set the new key to false.

   Signed-off-by: Juergen Gross [off-list ref]
   Signed-off-by: Peter Zijlstra (Intel) [off-list ref]
   Acked-by: Waiman Long [off-list ref]
   Cc: Linus Torvalds [off-list ref]
   Cc: Peter Zijlstra [off-list ref]
   Cc: Thomas Gleixner [off-list ref]
   Cc: akataria@vmware.com
   Cc: boris.ostrovsky@oracle.com
   Cc: chrisw@sous-sol.org
   Cc: hpa@zytor.com
   Cc: jeremy@goop.org
   Cc: rusty@rustcorp.com.au
   Cc: virtualization@lists.linux-foundation.org
   Cc: xen-devel@lists.xenproject.org
   Link: http://lkml.kernel.org/r/20170906173625.18158-2-jgross@suse.com
   Signed-off-by: Ingo Molnar [off-list ref]
---
arch/x86/include/asm/qspinlock.h | 11 ++++++++++-
arch/x86/kernel/paravirt.c       | 14 ++++++++++++--
arch/x86/kernel/smpboot.c        |  2 ++
3 files changed, 24 insertions(+), 3 deletions(-)

Thanks,
Fengguang